Weaving of textile fabrics



p 1954 w. w. DENNISON ETAL 87 WEAVING OF TEXTILE FABRICS 2 Sheets-Sheet1 Filed April 18 1951 INVENTORS.

N B U mam M DA D O W. CE T R M M E R AT L WCW Sept. 21, 1954 w. w.DENNISON ETAL 8 WEAVING OF TEXTILE FABRICS v v 2 Sheets-Sheet 2 FiledApril 18, 1951 INVENTORS. WILLIAM W. DENN ISON CHESTER C. ABRAMSONWALTER E. DAVIS AT TORN EYS.

Patented Sept. 21, 1954 WEAVING F TEXTILE FABRICS William W. Dennison,West Englewood, N. .L, and Chester 0. Abra-mean, Lavale, and Walter E.Davis, Cumberland, Md., assignors to 'Oelanese Corporation of Americ,poratinn of Delaware a. New York, N. Y., a col-'- ApplicationApl-il 13,1951, Serial No. 221,652

This invention relates to the weaving of textile fabrics and relatesmore particularly to a novel process and apparatus for the weaving oftextile such looms are normally equipped to prevent the production ofdefective fabrics. After correcting whatever conditions necessitated thestopping of the looms, the said looms are started again by the operatorto continue the weavin 0f the textile fabrics. The stoppin and startingof th'elooms produces noticeable marks on the woventextile fabrics,which marks are commonly called stop marks or set marks. While these setmarksare not too noticeable in certain types of woven textile fabricsand therefore dot not greatly affect their commercial value, they arevery noticeable and therefore highly objectionable in other types ofwoven textile fabrics and the presence of more than 'a very small numberof these set marks in apiece of these latter types of woven textilefabrics leads to the downgrading, of said fabrics.

It is an important object of this invention to provide a novel processand apparatus for the production of woven textile fabrics which will befree from the foregoing and other difficulties and) which willbeespecially efficient in operation and simple in construction.

A further object of this invention is to provide a process and a paratusfor the production of woven textile fabrics substantially free from setmarks.

Other objects of this invention, together with certain details ofconstruction and combinations of parts, will be apparent from'thefollowing detailed description and claim.

It has been discovered that when a loom is stopped, the tension on thewarp yarns that have" not yet been woven into the textile fabric tendsto remove some of the crimp from the warp yarns in that portion offabric positioned between the breast beam over which the textile fabricpasses on its way to the take-up roll, and the fell of the fabric, i. e.the edge or the fabric which is closest to the reed of the loom. Whenthe loom-is started up after having been stopped, the first few picksare over-beaten into the fabric resulting in a tight set mark. Moving ofthe fell of the fabric to the position it occupied before the loom wasstopped does not successfully eliminate the .set

marks although it does reducetheir noticeability' in some types offabrics.

1 Claim. '(Cl. 139-316) It has been found th t substantially toeliminate all traces of a set mark the fell of the fabric must be moved,before the loom on which said fabric is being woven is again started, toa posi-- tion closer to the reed-0f the loom than the position itoccupiedwhen the m was stopped. The precise position to which the fellof the woven textile fabric must be moved before starting the loom willdepend upon the nature of textile fabric being woven and of the loomemployed in the weaving operation. Howevergin the weaving of manydifferent types of textile fabrics on several different types of looms,the set marks have been substantially eliminated from said fabrics bymoving the fell of the fabric, before again starting a loom once it hasbeen stopped, to a position from about 0.060 to 0.090 inch closer to thereed of the loom than the position it occupied before the loom wasstopped; the exact distance for any type of fabric bein readilydetermined by the loom operator. The fell of the fabric may "bepositioned at any desired point by rotating the pick wheel of the loom,as is well understood in the art.

Any suitable measuring means may be employed accurately to determine theposition the fell of the fabric after thefloom has stopped and before itis again started, which measuring means may, for example, be optical,electrical or mechanical in nature. Optical means have been found to beespecially well suited for this purpose since they enabl'ethe fell ofthe fabric to be magnified to any desired extent so that its positionmay be determined accurately wi'th a minimum of difficulty. The opticalmeans may comprise a suitable magnifier or microscope mounted to viewthe fell of the fabric, or an optical projector suitably positioned tocast an image of the fell of the fabric onto a screen. In positioningthe fell of the fabric before the loom is started, more reproducible andmore accurate results are obtained if the measurement of said positionis made, not on the last pick in thefa'bric, but on the pick nextadjacent thereto.

While the positioning of the fell of the fabric in the manner describedabove will substantially eliminate the set marks from the fabric, it hasbeen discovered that "theappearance of the fabric'may be improved evenfurther if the tenstopped without the necessity for special action onthe part of the loom operator. For example, means may be provided torelease the pawl on the pick wheel when the loom is stopped therebyeffectively removing the tension on the fabric and the warp of yarns. Inthis case, the loom may also be provided with braking means which willautomatically engage the pick wheel when the pawl is disengagedtherefrom to limit the speed of rotation of said pick wheel and toprevent overrunning of the fabric roll to which said pick wheel issecured.

A preferred embodiment of the apparatus of this invention is shown inthe accompanying drawings wherein:

Fig. l is a diagrammatic side elevational view of the loom,

Fig. 2 is a detail view, on an enlarged scale, of

a portion of the loom shown in Fig. 1,

Fig. 3. is a plan view, on an enlarged scale, of a portion of the loomshown in Fig. 1,

Fig. 4 is a detail cross-sectional view, on an enlarged scale, takenalong the line 44 in Fig. 3 in the direction of the arrows, and

Fig. 5 is a showing of the field of the microscope when the fell of thefabric is positioned properly.

Referring now to the drawings, the reference numeral I designates a warpbeam from which a warp of yarns I2 is drawn under suitable tension overa whip roll l3 which is usually loaded by means of springs, weights, orthe like (not shown) From the whip roll I3, the warp yarns l2 are passedthrough a stop motion device l4 and are then threaded between lease rodsIE to separate the yarns into two groups. After leaving the lease rodsl5, the warp yarns |2.pass through harnesses l6 which raise and lowerselected yarns in any desired sequence to form a shed ll. Positioned infront of the harnesses l6 is'a lay or batten l8 which carries araceplate l9 and is provided with a reed 2| between the dents of whichthe warp yarns l2 are threaded. A'shuttle 22, riding on the raceplate l9and guided by the reed 2|, passes through the shed I! to lay a fillingyarn or pick 23 into the said shed. After the shuttle 22 has passedthrough the shed II, the batten I8 is moved from the position shown infull lines to the position shown in dotted lines in Fig. l of thedrawings to beat the pick 23 into its proper position in fabric 24, thefell of which is indicated by reference numeral 25. The fabric 24 thenpasses over a breast beam 26, around a positively driven sand roll ortake-up roll 21, over a guide roll 28 and is wound onto a fabric roll orcloth roll 29. There is provided in the loom a ratchet wheel or pickwheel 30 equipped with a pawl 3 |,'which pick wheel is connected throughsuitable means (not shown) to the take-up roll 21 and the cloth roll 29and is driven stepwise in synchronism with the operation of the loom totake up the fabric at the rate it is produced. It is to be understoodthat the construction and operation of the loom described above isentirely conventional.

When the loom is stopped, either through the operation of the stopmotion device l4 or in any other manner, brake arm 32 of the loom willdrop from the position shown in full lines to the position shown indotted lines in Fig. 2 of the drawings and shipper arm 33 of the loomwill rotate clockwise about pivot 34 on which it is mounted, all in amanner well known in the art. The rotation of the shipper arm 33 willcarry rod 35, which is secured to the shipper arm 33 by means of abracket 33, into contact with the pawl 3|, releasing the said pawl fromengagement with the pick wheel 30 and thereby effectively removing thetension from the fabric 24 and the warp yarns l2. To limit the speed ofrotation of the pick wheel 30 and prevent overrunning of the cloth roll29 when the pawl 3| is released, the brake arm 32 is'provided with abracket 31 carrying a brake member 38 which will frictionally engagepick hand wheel 39 fastened to the pick wheel 30 when the brake arm 32drops on the stopping of the loom.

To position properly the fell 25 of the fabric 24 before the loom isagain started after it has been stopped, there is provided a measuringmeans, indicated generally by reference numeral 4|. The measuring means4| comprises a plate 42 fastened to the breast beam 26, which plate 42has an arm 43 secured thereto by means of a hinge 44. The arm 43 carriesa bracket arm 45 which extends over the fabric 24 and supports anadjustable mount, indicated generally by reference numeral 46, carryinga microscope 41. The mount 45 comprises a lower slide 43 which isfastened to the bracket arm 45 and has a stud 49 projecting upwardlytherefrom. An upper slide 5| having a slot 52 extending therethrough ispositioned adjustably on the lower slide 48 and is held against movementby means of a knurled nut 53 in threaded engagement with the stud 49.Fastenedto the upper slide 52 is a fitting 54 which carries themicroscope 41 and is provided with an adjusting rod 55 to enable themicroscope 4! to be focusedsharply on the fabric 24.

In starting the loom after it has once been stopped, the measuring means4| is moved manually to the position shown in Fig. 3 of the drawings.The pick hand wheel 39 is then rotated by the loom operator to applytension to the warp yarns l2 and the fabric 24 and to draw the fell 25of said fabric 24 under the microscope 41 until the pick 23, which isnext adjacent to the fell 25, is aligned with the index line 56 as shownin Fig. 5 of the drawings. In this position, the fell 25 is closer tothe reed 2| than it was when the loom was stopped. The measuring means4| is then pivoted about the hinge 44 to the position shown in dottedlines in Fig. 1 of the drawings so that it will not interfere with theoperation of.

In a process for the weaving of textile fabrics on a loom wherein theloom is stopped and started again during the weaving operation, thesteps of substantially eliminating set marks from the woven textilefabric, which comprises removing tension from the fabric and the warp ofyarns when the loom is stopped, whereby due to the release of tension,the fell of the fabric moves towards the reed of the loom, applyingtension to the fabric to move the fell thereof in a direction away fromthe reed to a different position which is between the position occupiedby the fell of the fabric after said release of tension and the positionoccupied by the fell of the fabric when the loom was stopped, saiddifferent position being about 0.060 to 0.090 inch from the positionoccupied by the fell of the fabric when the loom was stopped, and thenstarting the 100m when the fell of the fabric is in said diiferentposition.

References Cited in the file of this patent UNITED STATES PATENTS NumberNumber Name Date Hollins Mar. 2, 1915 Jenckes May 15, 1917 Northrop Jan.1, 1924 Astle Oct. 13, 1925 Gibbs May 14, 1935 Darwin June 13, 1950Sprouse May 8, 1951 Gosnell Apr. 1, 1952 FOREIGN PATENTS Country DateGermany Nov. 21, 1929

